I really think the reasons given in the article are the reasons I've heard more than anyone calling her a "stuffy Northerner intellectual". Specifically:

Some anger at her is residual resentment of her husband whose second term was mired in a long impeachment process stemming from an extramarital relationship. For some it's about her policies -- pro-gun control, for universal health care.

Others cite a personality they see as too aggressive and insincere.

It's the third I've heard the most, really.

I'm personally against her policies, but not those cited. She's mostly been working on, since becoming Senator, censoring video games -- something I strongly disagree with. And really, it's an example of how her policies in general reflect the "Protect the Children!" mantra that I really dislike.